Paint normally is supplied for the home use retail market in 1/2 pint, pint, quart and 1 gallon cylindrical metal containers formed of metal with removable tops. The removable tops of 1 gallon and smaller cans have a convoluted rim that is press fit into a matching rim, to form a tight seal. Paint poured from these cans into other containers (smaller cans, paint roller pans, etc.) for more efficient use, flows over and into the convoluted edge which inevitably contaminates the sealing area and runs down the side of the can and often on to work area forming a paint ring where the can sits. When a paint brush is dipped into the can and then drug across the curved rim area, paint also gets into the sealing area. Upon resealing the can, this contamination can result in a less than airtight seal and the remaining paint may dry out during storage. Due to the configuration of the top convoluted edge of the can being located radially inward from the periphery, it is difficult to get all of the paint poured out causing waste and disposal concerns.
Paint is also sold in larger containers such as a standard 5 gallon metal or plastic container. The lids of these containers are often provided with a small removable seal cap. Paint can be poured from the 5 gallon can through the seal cap or by removing the complete lid. This contaminates with paint the top area around the seal cap and usually the side of the can. Paint can also be removed from the 5 gallon cans with power suction lines. Insertion of the suction lines and strainers usually requires the complete top of a 5 gallon can to be removed which breaks the seal.
Unused paint is usually stored in its original can. Repeated opening and closing of the top gradually reduces the sealing capability allowing air and moisture to enter or paint to seep out when can is upset. Each repeated opening becomes more difficult to effect a tight seal. The external surfaces of the I gallon and smaller cans easily rusts when exposed to humid conditions. Since the convoluted seal is not very tight due to paint and rust contamination, moisture gets inside the can which causes rusting and contamination of the remaining good paint unless rust prevention interior coatings are used. This rusting in the rim area also makes it difficult to subsequently remove the top, and after only a few openings, pliers are usually required. Liquid paint left in the convoluted seal as a result of pouring inevitably splatters when the top is pressed or hammered into place.
The cylindrical shape of any can of any size does not provide for economical shipping and storage of paint. One gallon cans are usually shipped in cardboard boxes, 4 to a box. Up to about 27% of the available shipping space is not used. One and 5 gallon cans are stored and displayed in stores and warehouses in stacked columns with up to about 27% wasted space.
Many adapters have been devised for attachment to the top of paint cans. These have had only limited success in solving the problems discussed above.
Water coolers with swivel pour valves are commercially available, and many square cans made of both plastic and metal are used commercially for the containment of a great variety of products.
What is needed is an effective clean paint can. Such a can should be capable of providing a means for discharging all of its contents by power spray equipment or in a narrow controllable stream, without concern for drips, runs, spills or contamination of sealing surfaces, loss of sealing capability with each opening and closing, waste of paint left in can, spattering during replacement of the top, corrosion contamination during storage, loss of shipping and storage space, access by power paint spraying suction lines and strainers, and storage of unused paint with minimum concern for messy spills, drips, contamination and subsequent loss of contents. It should be opened and resealed without the need for screwdrivers, pliers or hammers.